Question: Simplify the following expression: ${-(6+2a)+3(3a+1)}$
The minus sign in front of the parentheses means we multiply each term inside the first parentheses by ${-1}$ $ {-1(}\gray{6+2a}{)} + 3(3a+1) $ $ {-6-2a} + 3(3a+1) $ Distribute the ${3}$ into the parentheses: $ -6-2a + {3(}\gray{3a+1}{)} $ $ -6-2a + {9a+3} $ Rewrite the expression to group the ${a}$ terms and numeric terms: $ {-2a + 9a} {-6 + 3}$ Combine the ${a}$ terms: $ {7a} {-6 + 3}$ Combine the numeric terms: $ {7a} {-3}$ The simplified expression is $7a-3$